TWISP TOWN OF
PWS ID: WA5390050 · Twisp, Washington 98856
Population Served
1,044
Total Violations
138
Health-Based Violations
8
Water Source
Groundwater
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 670
- County
- Okanogan
- School/Daycare
- No
- MCL Violations
- 8
- Monitoring Violations
- 130
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Nitrate | MR | 41 | 2022 |
| Coliform (TCR) | MCL | 8 | 2005 |
| Endrin | MR | 5 | 2005 |
| BHC-GAMMA | MR | 5 | 2005 |
| Simazine | MR | 5 | 2005 |
| Di(2-ethylhexyl) phthalate | MR | 5 | 2005 |
| Hexachlorocyclopentadiene | MR | 5 | 2005 |
| Atrazine | MR | 5 | 2005 |
| LASSO | MR | 5 | 2005 |
| Methoxychlor | MR | 5 | 2005 |
| Toxaphene | MR | 5 | 2005 |
| Heptachlor epoxide | MR | 5 | 2005 |
| Chlordane | MR | 5 | 2005 |
| HEXACHLOROBENZENE | MR | 5 | 2005 |
| Di(2-ethylhexyl) adipate | MR | 5 | 2005 |
| Heptachlor | MR | 5 | 2005 |
| Benzo(a)pyrene | MR | 5 | 2005 |
| Coliform (TCR) | MR | 4 | 2000 |
| Gross Alpha, Excl. Radon and U | MR | 1 | 1979 |
| Mercury | MR | 1 | 1979 |
| Chromium | MR | 1 | 1979 |
| Fluoride | MR | 1 | 1979 |
| Pentachlorophenol | MR | 1 | 2005 |
| Arsenic | MR | 1 | 1979 |
| Barium | MR | 1 | 1979 |
| Cadmium | MR | 1 | 1979 |
| Revised Total Coliform Rule | MON | 1 | 2020 |
| Selenium | MR | 1 | 1979 |
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025.
This data is provided for informational purposes only.